1. Field of the Invention
The present invention relates to an air conditioning apparatus of twin-floor type, which is designed to supply conditioned air in two directions in a room.
2. Description of the Related Art
Their is the trend that rooms are built larger and larger. The larger a room, the less uniform the temperature distribution in the room. An air conditioner has been developed which is designed to supply conditioned air in two directions in a room, to thereby render the temperature distribution uniform in the room. This air conditioner comprises an indoor unit to be secured to the ceiling of a room. The indoor unit has two indoor heat exchangers and two indoor fans. The indoor fans are driven to take indoor air into the respective indoor heat exchangers and to supply the air conditioned thereby in different directions in the room.
Twin-floor type air conditioners are disclosed in, for example, Jpn. UM Appln. KOKOKU Publication No. 59-6174 and Jpn. UM Appln. KOKAI Publication No. 1-53812.
The air conditioner disclosed in Jpn. UM Appln. KOKOKU Publication No. 59-6174 comprises an indoor unit (C) which incorporates two heat exchangers (8, 9), an upper fan (6) and a lower fan (7). The upper fan (6) is used to draw indoor air through an air inlet (2) and supply the indoor air via the first heat exchanger (8) back into the room in a first direction. On the other hand, the lower fan (7) is used to draw the in door air through the air inlet (2) and supply the indoor air via the second heat exchanger (8) back into the room in a second direction. The upper fan (6) and the lower fan (7) can be rotated at various speeds, independently of each other.
The air conditioner disclosed in Jpn. UM Appln. KOKAI Publication No. 1-53812 comprises an indoor unit (1) to be installed on the ceiling of a room. The indoor unit (1) has an air inlets (2) formed in the lower side. The indoor unit (1) incorporates two indoor heat exchangers (3, 4) and two fans (5, 6). The indoor heat exchangers (3, 4) are inclined, and the fans (5, 6) are arranged near the heat exchangers (3, 4), respectively. The indoor unit (1) has two air outlets (7, 8) in the lower side. The air outlets (7, 8) are located at such positions that air may flow through them from the fans (5, 6) into the room.
A twin-floor type air conditioner, as well as any other conventional air conditioner, may supply cold air into the room, making any occupant of the room feel cold, when it starts heating operation. This is because neither indoor heat exchanger has not heated air sufficiently. During the heating operation, the high-pressure side pressure of the refrigerating cycle unit may increases excessively, shortening the lifetime of the components of the refrigerating cycle unit. During the cooling operation, the drain on either indoor heat exchanger may be frozen sometimes.
To prevent these undesirable events, the rate at which the indoor fans supply air into the room may be adjusted. In practice, however, it is very difficult to control both indoor fans to adjust the air supply rate appropriately.